1. Field of the Invention
This invention relates to an improved anchoring arrangement for use in conjunction with cavity walls. More particularly, the invention relates to construction accessory devices, namely, veneer ties with vertically compressed cavity portions, and a sealing anchoring system for insulated cavity walls. The invention is applicable to structures having an outer wythe of brick or stone facing in combination with an inner wythe of either masonry block or dry wall construction. The system has application to non-seismic and seismic-resistant structures.
2. Description of the Prior Art
In the past, investigations relating to the effects of various forces, particularly lateral forces, upon brick veneer masonry construction demonstrated the advantages of having high-strength wire anchoring components embedded in the bed joints of anchored veneer walls, such as facing brick or stone veneer. Anchors and ties are generally placed in one of the following five categories: corrugated; sheet metal; wire; two-piece adjustable; or joint reinforcing. The present invention has a focus on wire formative veneer ties.
Prior tests have shown that failure of anchoring systems frequently occurs at the portion of the veneer tie that lies within the cavity. The prior art veneer tie cavity sections often retain stray mortar and moisture within the cavity. The vertical (north-south) compression of the veneer tie cavity portion strengthens the cavity portion and causes a shedding of the excess mortar and moisture retained on the prior art veneer ties. This invention addresses the need for a high-strength veneer tie interconnection suitable for use with both a masonry block or dry wall construction and provides a tie-to-receptor connection.
In the late 1980's, surface-mounted wall anchors were developed by Hohmann & Barnard, Inc., now a MiTek-Berkshire Hathaway company, patented under U.S. Pat. No. 4,598,518 ('518). This invention was commercialized under trademarks DW-10®, DW-10-X®, and DW-10-HS®. These widely accepted building specialty products were designed primarily for drywall construction, but were also used with masonry backup walls. For seismic applications, it was common practice to use these wall anchors as part of the DW-10 Seismiclip® interlock system which added a Byna-Tie® wire formative, a Seismiclip® snap-in device—described in U.S. Pat. No. 4,875,319 ('319), and continuous wire reinforcement.
In the dry wall application, the surface-mounted wall anchor of the above-described system has pronged legs that pierce the insulation and the wallboard and rest against the metal stud to provide mechanical stability in a four-point landing arrangement. The vertical slot of the wall anchor enables the mason to have the wire tie adjustably positioned along a pathway of up to 3.625-inch (max). The interlock system served well and received high scores in testing and engineering evaluations which examined the effects of various forces, particularly lateral forces, upon brick veneer masonry construction. However, under certain conditions, the system did not sufficiently maintain the integrity of the insulation.
The engineering evaluations further described the advantages of having a continuous wire embedded in the mortar joint of anchored veneer wythes. The seismic aspects of these investigations were reported in the inventor's '319 patent. Besides earthquake protection, the failure of several high-rise buildings to withstand wind and other lateral forces resulted in the incorporation of a continuous wire reinforcement requirement in the building code provisions. The use of a continuous wire in masonry veneer walls has also been found to provide protection against problems arising from thermal expansion and contraction and to improve the uniformity of the distribution of lateral forces in the structure.
Exemplary of the public sector building specification is that of the Energy Code Requirement, Boston, Mass. (see Chapter 13 of 780 CMR, Seventh Edition). This code sets forth insulation R-values well in excess of prior editions and evokes an engineering response opting for thicker insulation and correspondingly larger cavities. Here, the emphasis is upon creating a building envelope that is designed and constructed with a continuous air barrier to control air leakage into or out of conditioned space adjacent the inner wythe.
Shortly after the introduction of the pronged wall anchor, a seismic veneer anchor, which incorporated an L-shaped backplate, was introduced. This was formed from either 12- or 14-gage sheetmetal and provided horizontally disposed openings in the arms thereof for pintle legs of the veneer anchor. In general, the pintle-receiving sheetmetal version of the Seismiclip® interlock system served well, but in addition to the insulation integrity problem, installations were hampered by mortar buildup interfering with pintle leg insertion.
In the 1980's, an anchor for masonry veneer walls was developed and described in U.S. Pat. No. 4,764,069 by Reinwall et al., which patent is an improvement of the masonry veneer anchor of Lopez, U.S. Pat. No. 4,473,984. Here the anchors are keyed to elements that are installed using power-rotated drivers to deposit a mounting stud in a cementitious or masonry backup wall. Fittings are then attached to the stud which include an elongated eye and a wire tie therethrough for disposition in a bed joint of the outer wythe. It is instructive to note that pin-point loading—that is forces concentrated at substantially a single point—developed from this design configuration. Upon experiencing lateral forces over time, this resulted in the loosening of the stud.
In the past, the use of wire formatives have been limited by the mortar layer thickness which, in turn are dictated either by the new building specifications or by pre-existing conditions, e.g. matching during renovations or additions to the existing mortar layer thickness. While arguments have been made for increasing the number of the fine-wire anchors per unit area of the facing layer, architects and architectural engineers have favored wire formative anchors of sturdier wire.
Contractors found that heavy wire anchors, with diameters approaching the mortar layer height specification, frequently result in misalignment. This led to the low-profile wall anchors of the inventors hereof as described in U.S. Pat. No. 6,279,283. However, the above-described technology did not fully address the adaption thereof to insulated inner wythes utilizing stabilized stud-type devices.
As insulation became thicker, the tearing of insulation during installation of the pronged DW-10X wall anchor, see supra, became more prevalent. This occurred as the installer would fully insert one side of the wall anchor before seating the other side. The tearing would occur during the arcuate path of the insertion of the second leg. The gapping caused in the insulation permitted air and moisture to infiltrate through the insulation along the pathway formed by the tear. While the gapping was largely resolved by placing a self-sealing, dual-barrier polymeric membrane at the site of the legs and the mounting hardware, with increasing thickness in insulation, this patchwork became less desirable. The improvements hereinbelow in surface mounted wall anchors look toward greater retention of insulation integrity and less reliance on a patch.
The high-strength veneer tie of this invention is specially configured to prevent veneer tie failure and resultant pullout. The configured tie restricts movement in all directions, ensuring a high-strength connection and transfer of forces between the veneer and the backup wall. The wire formative cavity portions are compressively reduced in height by the cold-working thereof to increase the veneer tie strength. Because the wire formative hereof employs extra strong material and benefit from the cold-working of the metal alloys, the high-span anchoring system meets the unusual requirements demanded in current building structures. Reinforcement wires are included to form seismic constructs.
The following patents are believed to be relevant and are disclosed as being known to the inventor hereof:
U.S. Pat. No.InventorIssue Date4,021,990SchwalbergMay 10, 19774,373,314AllanFeb. 15, 19834,473,984LopezOct. 2, 19844,598,518HohmannJul. 8, 19864,875,319HohmannOct. 24, 19895,456,052Anderson et al.Oct. 10, 19956,209,281RiceApr. l 3, 20016,279,283Hohmann et alAug. 28, 20016,851,239Hohmann et alFeb. 8, 20057,017,318HohmannMar. 28, 20067,325,366Hohmann, Jr., et al.Feb. 5, 2008
U.S. Pat. No. 4,021,990-Schwalberg-Issued May 10, 1977 Discloses a dry wall construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheetmetal anchor. Like Storch '764, the wall tie is embedded in the exterior wythe and is not attached to a straight wire run.
U.S. Pat. No. 4,373,314-Allan-Issued Feb. 15, 1983 Discloses a vertical angle iron with one leg adapted for attachment to a stud; and the other having elongated slots to accommodate wall ties. Insulation is applied between projecting vertical legs of adjacent angle irons with slots being spaced away from the stud to avoid the insulation.
U.S. Pat. No. 4,473,984-Lopez-Issued Oct. 2, 1984 Discloses a curtain-wall masonry anchor system wherein a wall tie is attached to the inner wythe by a self-tapping screw to a metal stud and to the outer wythe by embedment in a corresponding bed joint. The stud is applied through a hole cut into the insulation.
U.S. Pat. No. 4,598,518-Hohmann-Issued Jul. 7, 1986 Discloses a dry wall construction system with wallboard attached to the face of studs which, in turn, are attached to an inner masonry wythe. Insulation is disposed between the webs of adjacent studs.
U.S. Pat. No. 4,875,319-Hohmann-Issued Oct. 24, 1989 Discloses a seismic construction system for anchoring a facing veneer to wallboard/metal stud construction with a pronged sheetmetal anchor. The wall tie is distinguished over that of Schwalberg '990 and is clipped onto a straight wire run.
U.S. Pat. No. 5,456,052-Anderson et al.-Issued Oct. 10, 1995 Discloses a two-part masonry brick tie, the first part being designed to be installed in the inner wythe and then, later when the brick veneer is erected to be interconnected by the second part. Both parts are constructed from sheetmetal and are arranged on substantially the same horizontal plane.
U.S. Pat. No. 6,209,281-Rice-Issued Apr. 3, 2001 Discloses a masonry anchor having a conventional tie wire for mounting in the brick veneer and sheetmetal bracket for mounting on the metal-stud-supported drywall. The bracket has a slit which is vertically disposed when the bracket is mounted on the metal stud and, in application, protrudes through the drywall into the cavity. The slit provides for a vertically adjustable anchor.
U.S. Pat. No. 6,279,283-Hohmann et al.-Issued Aug. 28, 2001 Discloses a low-profile wall tie primarily for use in renovation construction where in order to match existing mortar height in the facing wythe a compressed wall tie is embedded in the bed joint of the brick veneer.
U.S. Pat. No. 6,851,239-Hohmann et al.-Issued Feb. 8, 2005 Discloses a high-span anchoring system described for a cavity wall incorporating a wall reinforcement combined with a wall tie, which together serve a wall construct having a larger-than-normal cavity. Further the various embodiments combine wire formatives which are compressively reduced in height by the cold-working thereof. Among the embodiments is a veneer anchoring system with a low-profile wall tie for use in a heavily insulated wall.
U.S. Pat. No. 7,017,318-Hohmann, et al.-Issued Mar. 28, 2006 Discloses an anchoring system with low-profile wall ties in which insertion portions of the wall anchor and the veneer anchor are compressively reduced in height.
U.S. Pat. No. 7,325,366-Hohmann, Jr., et al.-Issued Feb. 5, 2008 Discloses snap-in veneer ties for a seismic construction system in cooperation with low-profile, high-span wall anchors.
The present invention provides an advancement in anchoring systems. The use of high-strength, compressed wire formatives at key locations in the veneer tie provides added strength in the cavity.
None of the above references provide the innovations of this invention. As will become clear in reviewing the disclosure which follows, the insulated cavity wall structures benefit from the recent developments described herein that lead to solving the problems of veneer tie interconnection failure. This invention relates to an improved anchoring arrangement for use in conjunction with cavity walls having an inner wythe and an outer wythe and meets the heretofore unmet needs described above.